Overpants are kind of a personal thing that you have to experiment with yourself. They usually come in two varieties, leather or cordura. I have had both, a leather set of overpants from FoxCreek and a cordura set from Motorport. The thing I didn't like about the leather overpants is that they are bulky, and I'm a fairly slim guy (5'7" 145lbs 32" waist). When I wear them I feel thick in the waist and hips because I am wearing undies, jeans, and then leather overpants. That's quite a few layers of waist bands on top of each other. The thickness was such that I use suspenders instead of a belt to hold them up. I also found that they bunched up when seated. If you look at your jeans now you will see that there are gathered folds in your lap. Now image that same effect in leather over the jeans. One of the reasons chaps are popular (although many argue about coverage and safety) is that the open front and backside reduces the amount of layering in those areas. I had the same experience with the cordura pants when I rode sport/tour bikes. So I went one size smaller and wore them without jeans. I really can't help you with an antifog helmet because I use an open face.